Variable-format cinematographic apparatus

ABSTRACT

Cinematographic apparatus, e.g., film projector, can accommodate film of different formats, especially normal 8 mm and Super-8 film. A sensing device distinguishes between the film types by the differences in the configuration of the respective marginal perforations in the films. Specifically, the sensing device is in the form of a finger, forming one part of an electric contact and capable of penetrating through only one of the film types to engage the other part of the contact on the other side of the film. The finger controls the displacement of other elements necessary for the adaptation of the apparatus to different film formats.

United States Patent Sekera 1 Aug. 22, 1972 [72] Inventor: Jaroslav Sekera, Yverdon, Switzerland [73] Assignee: Paillard S.A., Sainte-Croix, Vaud,

Switzerland [22] Filed: Sept. 14, 1970 [21] Appl. No.: 71,927

[30] Foreign Application Priority Data Oct. 3, 1969 Switzerland ..l4896/69 [52] US. Cl. ..352/79 [5 1] Int. Cl. ..G03b 21/50 [58] Field of Search ..352/79 [56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,240,395 5/ 1967 Germany ..359/79 I W 20 II QJIL Primary Examiner-Samuel S. Matthews Assistant Examiner-Russell E. Adams, Jr. Attorney.Emory L. Groff and Emory L. Groff, Jr.

[57] ABSTRACT Cinematographic apparatus, e.g., film projector, can accommodate film of different formats, especially normal 8 mm and Super-8 film. A sensing device distinguishes between the film types by the differences in the configuration of the respective marginal perforations in the films. Specifically, the sensing device is in the form of a finger, forming one part of an electric contact and capable of penetrating through only one of the film types to engage the other part of the contact on the other side of the film. The finger controls the displacement of other elements necessary for the adaptation of the apparatus to different film formats.

4 Claims, 8 Drawing Figures PATENTED 1:22 m2 SHEET 1 [IF INVENTOR JA/QASL/W SE 5,5

ATTORNEY VARIABLE-FORMAT CINEMATOGRAPHIC APPARATUS Cinematographic projectors intended for the projection of different formats of films, especially 8 mm, 9.5 mm and 16 mm, have been known for a very long time. In these projectors a certain number of parts are provided which need to be changed for adaptation to the different film formats. In particular such parts include the optical system, the gate with the projection aperture, the claw mechanism and the feeding devices.

Following the appearance on the market of the Super-8 type of film side-by-side with the normal 8 mm format, several manufacturers have produced multiformat projectors including at least a displaceable element, the position of which depends on the formate selected, and a means for controlling the position of said element.

Indeed, for these relatively similar formats, certain components need not be replaced when a change-over is made from projecting film of one format to the other. Such components are, more particularly, the optical system and the gate. Parts which must be changed or adapted are the projection aperture, the claw mechanism and the sprocket-wheel, when the apparatus is provided with the latter.

At any rate, a user of the apparatus must act on at least one control means for adapting the projector to the size of the film he wishes to project. Should he forget to do this operation, there may be a risk that the film is damaged by the parts of the apparatus which had not been adapted to the selected film format.

The object of the present invention is to liberate the user from having to regulate his apparatus in dependence on the selected film format.

According to this invention, there is therefore provided a variable-size cinematographic apparatus including at least one displaceable element the position of which depends on the format of the film selected, means for controlling the position of said element, a device for sensing the format of the film placed in the apparatus, said device being associated with the control means automatically to ensure the adaptation of the apparatus to the selected film format and including a feeler element adapted to cooperate with the perforations of the film so as to recognize a specific distinguishing characteristic of said perforations.

Preferably, the feeler element is constituted by a finger which is in use resiliently urged into contact with the film, the dimensions of this finger being such as to be capable of penetrating into the perforations of only one of the types of film, while the location of this finger is chosen so that at least a portion of the surface of the finger is situated outside the path of movement of the perforations of the or each other type of film.

The feeler element may constitute a part of an electric contact, there being another part which is situated on the other side of the film, whereby the feeler element must in operation penetrate into a perforation of the film in order to make contact with the other contact art. p Preferably, said one displaceable element is a plate movement of which causes an appropriate projection aperture to be brought into a projecting position.

The invention is described, by way of example only, with reference to the accompanying drawings, which show schematically a preferred embodiment of a cinematographic apparatus, in the form of a cine projector, according to this invention.

FIG. 1 is an elevational view of the projector.

FIG. 2 is an explanatory view showing a portion of Super-8 type film on which the perforations corresponding to normal 8 mm film are shown in dotted lines.

FIGS. 3 and 4am respectively a longitudinal section on the line of perforations and a plan view of a Super-8 film with a feeler finger forming part of the apparatus of this invention.

FIGS. 5 and 6 are views respectively corresponding to FIGS. 3 and 4, but for the case of a normal 8 mm film.

FIGS. 7 and 8 show in transverse section the functioning of the feeler finger when the film moves, respectively for Super-8 type and normal 8 mm type.

Referring to the drawings and particularly to FIG. 1, the projector includes a housing 1, a casing 2 sheltering a projection lamp, a gate or passageway 3 and an objective 4. The film F is placed on a feeding spool 5 and is in use wound on a take-up spool 6 after passing through the gate 3. Upstream of gate 3, the film is arranged to pass along a device 7 which is adapted to. detect or sense film format and which will be described below. Between the spool 5 and the device 7, the film in operation passes a roller 8 carried by an arm 9 mounted resiliently on the housing 1; the roller 8 serves to eliminate the transmission of the jerks of the film during its passage in the gate 3 to the feeding spool 5.

At the entry to, and the exit from, the gate 3 the film F is passed between respective movable guides 10, 11, 10', 11' which are arranged to be brought near to each other to permit the automatic threading of film and its guidance to the take-up spool 6. Before arriving at the latter, the film is led in the proximity of a watching roller 12 adjacent the exit of the gate 3. The roller 12 is mounted on a lever 13 mounted for pivoting about the driving shaft of a pulley 14 and carrying a roller 15 driven by the pulley 14. When the film loop becomes too large, the roller 12 is released and causes the lever 13 to pivot to bring the roller 15, the periphery of which is rubberized, into contact with the periphery of the spool 6 to rotate the latter. When the loop becomes too small, the roller 12 is lifted and disengages the roller 15 from the spool 6 to interrupt the driving engagement therebetween.

FIG. 2 shows on the same piece of film F the perforations 16 corresponding to Super-8 format and perforations 17 shown in dotted lines, of the normal 8 mm format of film. As can be seen, the positions and dimensions of the two sets of perforations are different such that these constitute a distinctive feature of the type of film. The sensing device 7 includes a feeler finger l8, il- Iustrated in FIGS. 3 to 8, which is provided to recognize the perforations of the film. This finger 18 is guided in an insulating support 19 and, under the action of a spring 20, can penetrate into the perforations of Super- 8 type film. A stop 25 of the finger 18 is then in electric contact with a thin conducting strip 26 on the other side of the film to close a non-illustrated electric circuit.

When the film used is of normal 8 mm format, the finger 18 cannot penetrate into the perforations and cannot make the electric circuit. In face, the perforations 17 of the normal 8 mm type film are at a distance a from the edge of the film, which is greater than the distance b from the same edge for the perforations 16 of the Super-8 format, as shown in FIG. 7. The finger 18 has at least a portion of its surface outside the path of movement of the perforations 17 of the 8 mm film, as can be seen in FIG. 8.

FIGS. 7 and 8 show also a displaceable plate 21 along the gate 3. which plate has two apertures: 22 (FIG. 7) and 23 (FIG. 8) corresponding to the projection apertures for each of the two film types. By displacing this plate 21, one can bring the appropriate sized projection aperture into alignment with an opening 24 provided in a member 27 bounding the gate 3. This plate 21 could be subjected to the action of a return spring (not shown) for urging it into the position for projecting normal 8 mm film, and subjected to the action of an electromagnet (not shown) displacing it against the bias of this return spring to bring it into the position for projecting Super-8 film. The electromagnet can be controlled by the contact between the finger 18 and the part 27. This electromagnet must have delayed action to avoid its displacement each time the said contact is interrupted in the course of the movement of the perforations. The delay for the electromagnet can be obtained by a known means employing a capacitor at the ends of the electromagnet windings, or by providing a few short-circuiting turns on these windings.

It is clear that in the case where the cinematographic projector has other elements which have to be adapted to the projected film format, the said electric circuit can also be used to control the change of these elements. Particularly, this could apply to the modification of the claw and sprocket-wheel, and in the case where the formats to be used have greater differences therebetween than those between normal 8 mm and Super-8 film formats, any changes in the optical system can also be controlled thereby.

A number of modifications can be made to the above-described apparatus, and this apparatus is not exclusively applicable to projectors but also to variable-size cameras. Clearly the electric contact serving to recognize or sense the film perforations could be used differently, e.g. to close in the case of normal 8 mm type of film and to stay open for Super-8 film. In place of the contact closing between the stop 25 and the strip 26, one could envisage the location of the contact directly between the end of the finger l8 and the part 27 bounding the gate 3.

One could provide several contacts to distinguish one type of film from another, eg by measuring their longitudinal spacing (pitch) and not their position relative to the edge of the film.

It is also apparent that in place of providing a mechanical part as contact, one could very well control the position relative to the edge or the pitch of the perforations with the aid of a pencil of light and photoelectric elements.

I claim:

1. A variable-format cinematographic apparatus for use with film having marginal perforations, including at least one displaceable element the position of which depends on the format of the film selected, means for controlling the position of said element, a device for detectlng the format of the film placed 1n the apparatus, said device being operatively associated with the control means for automatically ensuring the adaptation of the apparatus to the format of the film that is being used, and a feeler element forming part of said device to cooperate with the perforations of the film to recognize a specific distinguishing characteristic of said perforations.

2. Apparatus according to claim 1, in which the feeler element comprises a finger, means resiliently to press said finger against the film, the dimensions of this finger being such as to be capable of penetrating into the perforations of only one of the types of film, said finger being so located that at least a portion of the surface of the finger being situated outside the path of movement of the perforations of all the other types of film.

3. Apparatus according to claim 1, including electric contact means of which the feeler element constitutes one part, the other contact part situated on the other side of the film, and the contact is closed when said feeler element penetrates into a perforation of the film used.

4. Apparatus as claimed in claim 1, wherein said at least one displaceable element is a plate, there being projection apertures associated with the different film formats and connected to said plate so as to bring the appropriate one to a projecting position. 

1. A variable-format cinematographic apparatus for use with film having marginal perforations, including at least one displaceable element the position of which depends on the format of the film selected, means for controlling the position of said element, a device for detecting the format of the film placed in the apparatus, said device being operatively associated with the control means for automatically ensuring the adaptation of the apparatus to the format of the film that is being used, and a feeler element forming part of said device to cooperate with the perforations of the film to recognize a specific distinguishing characteristic of said perforations.
 2. Apparatus according to claim 1, in which the feeler element comprises a finger, means resiliently to press said finger against the film, the dimensions of this finger being such as to be capable of penetrating into the perforations of only one of the types of film, said finger being so located that at least a portion of the surface of the finger being situated outside the path of movemenT of the perforations of all the other types of film.
 3. Apparatus according to claim 1, including electric contact means of which the feeler element constitutes one part, the other contact part situated on the other side of the film, and the contact is closed when said feeler element penetrates into a perforation of the film used.
 4. Apparatus as claimed in claim 1, wherein said at least one displaceable element is a plate, there being projection apertures associated with the different film formats and connected to said plate so as to bring the appropriate one to a projecting position. 